The FDA on Sept. 14, 2017 approved MYASI® (Bevacizumab-awwb) as a Biosimilar to AVASTIN® (Bevacizumab). MYASI® is the first Biosimilar approved in the U.S. for the treatment of cancer. A Biosimilar must show that it has no clinically meaningful differences in terms of safety and effectiveness from the already approved biological product (also known as reference product). A Biosimilar product can only be approved by the FDA if it has the same mechanism of action, route of administration, dosage form and strength as the reference product, and only for the indications and conditions of use, that have been approved for the reference product. The approval of MYASI® was based on comparisons of extensive structural and functional product characterization, animal data, human PharmacoKinetic and pharmacodynamic data, clinical immunogenicity, between MYASI® and AVASTIN® (Bevacizumab), and it was noted that MYASI® is highly similar to AVASTIN® and that there are no clinically meaningful differences between the two products.
Tag: General Medical Oncology & Hematology
Late Breaking Abstract – ASCO 2017 Single Dose Radiation Therapy as Effective as Multiple Fractions for Metastatic Spinal Cord Compression
SUMMARY: Metastatic Spinal Cord Compression (MSCC) first described by Spiller in 1925, is an oncologic emergency and is a well recognized complication of cancer. Approximately 10% of all patients with cancer develop metastatic disease to the spinal column. Even though any solid tumor can metastasize to the spine, more than 50% of MSCC cases are caused by breast cancer, prostate cancer and lung cancer. The risk of MSCC is particularly high in those patients with widespread malignancy and those with known spinal metastases. Pathological compression fracture of the vertebral body or direct tumor invasion can cause compression of the spinal cord or cauda equina resulting in irreversible neurological deficit as well as paraplegia. Common symptoms include back pain, tingling, numbness and difficulty walking. Early recognition of symptoms and prompt intervention is therefore imperative to prevent neurological damage.
Patients with MSCC, in addition to steroids, are often treated with Radiation Therapy (RT) to relieve pain and improve neurological function and mobility. There is however no standard Radiation Therapy schedule. ASTRO (American Society for Radiation Oncology) in its “Choosing Wisely” guidelines recommended not using extended fractionated schemes (more than 10 fractions) for palliation of bone metastases. Equivalent pain relief can be accomplished following 30 Gy in 10 fractions, 20 Gy in 5 fractions, or a single 8 Gy fraction. It was also recommended that strong consideration should be given to a single 8 Gy fraction, for patients with a limited prognosis or with transportation difficulties.
SCORAD III is a randomized phase III study which evaluated whether a single-dose Radiation Therapy (RT) was as effective as multifraction RT administered over 5 days, without compromising patient outcomes. Enrolled patients (N=688) were randomized 1:1 to receive External Beam spinal canal RT as a single dose of 8 Gy (N=345) or 20 Gy in 5 fractions (N=343). Eligible patients had spinal cord or cauda equina (C1-S2) compression, confirmed by MRI/CT scan, treatable within a single radiation field, with no prior RT to the same area and had a life expectancy of more than 8 weeks. The median age was 70 years, 73% were male and 44% had metastatic prostate, 18% had metastatic lung, 11% had metastatic breast and another 11% had metastatic GastroIntestinal cancers. Patients were stratified by Ambulatory Status (AS), site of primary, and presence or absence of non-skeletal metastases. The primary endpoint of the study was Ambulatory Status, measured on a four-point scale – Grade 1: Able to walk normally, Grade 2: Able to walk with a walking aid (such as a cane or walker), Grade 3: Has difficulty walking even with walking aids and Grade 4: Dependent on wheelchair. Two third of the patients (66%) were ambulatory with or without walking aids (Ambulatory Status of 1 to 2) at study entry.
It was noted that at 8 weeks, 69.5% of patients who received single-dose radiation therapy and 73.3% of those who received five doses had an Ambulatory Status of 1 to 2 and could walk normally or with a walking aid such as a cane or a walker, suggesting that both single dose and longer course radiation treatments helped patients with their mobility. The median Overall Survival was similar in the two treatment groups – 12.4 weeks with a single dose versus 13.7 weeks with five doses, and this was not statistically significant (HR=1.02; P=0.81). The proportion of patients experiencing severe side effects was similar in the two treatment groups (20.6% vs 20.4%), but mild side effects were less common in the single dose of 8 Gy group compared to those receiving multiple fractions (51% vs 56.9%).
The authors concluded that a single radiation dose of 8 Gy in patients with metastatic Spinal Cord Compression was non-inferior and was as effective as longer course multiple fractions, for Ambulatory Status at 8 weeks, as well as Overall Survival. They added that this would mean fewer hospital visits and more time with the family, at least for patients with a short life expectancy. It should however be noted that in this study, at the time of enrollment, majority of patients were fully ambulatory or were able to walk with a walking aid. Whether single dose radiation therapy is adequate for those patients with very advanced involvement of the spine, however remains to be seen. SCORAD III: Randomized non-inferiority phase III trial of single dose radiotherapy (RT) compared to multifraction RT in patients (pts) with metastatic spinal canal compression (SCC). Hoskin P, Misra V, Hopkins K, et al. J Clin Oncol. 35;2017 (suppl; abstr LBA10004).
IMBRUVICA® (Ibrutinib)
The FDA on August 2, 2017 approved IMBRUVICA® for the treatment of adult patients with chronic Graft Versus Host Disease (cGVHD), after failure of one or more lines of systemic therapy. This is the first FDA-approved therapy for the treatment of cGVHD. IMBRUVICA® is a product of Pharmacyclics LLC.
Antiemetics American Society of Clinical Oncology Clinical Practice Guideline Update (Part II)
SUMMARY: Chemotherapy Induced Nausea and Vomiting (CINV) is quite common and occurs in about 80% of patients receiving chemotherapy. The following (Part II) is a continuation of the ASCO Antiemetics Clinical Practice Guideline Update.
KEY RECOMMENDATIONS (ctd) – PART II
Adult Patients
Breakthrough nausea and vomiting
• (No change) For patients with breakthrough nausea or vomiting, clinicians should re-evaluate emetic risk, disease status, concurrent illnesses, and medications, and ascertain that the best regimen is being administered for the emetic risk.
• (Updated) Adult patients who experience nausea or vomiting despite optimal prophylaxis, and who did not receive Olanzapine prophylactically, should be offered Olanzapine in addition to continuing the standard antiemetic regimen.
• (Updated) Adult patients who experience nausea or vomiting despite optimal prophylaxis, and who have already received Olanzapine, may be offered a drug of a different class—for example, an NK1 receptor antagonist, Lorazepam or Alprazolam, a dopamine receptor antagonist, Dronabinol, or Nabilone—in addition to continuing the standard antiemetic regimen.
Anticipatory nausea and vomiting
• (Reworded for clarity) All patients should receive the most active antiemetic regimen that is appropriate for the antineoplastic agents being administered. Clinicians should use such regimens with initial antineoplastic treatment, rather than assessing the patient’s emetic response with less effective antiemetic treatment. If a patient experiences anticipatory emesis, clinicians may offer behavioral therapy with systematic desensitization.
KEY RECOMMENDATIONS
High emetic risk Radiation Therapy
• (Updated) Adult patients who are treated with high-emetic-risk radiation therapy should be offered a two-drug combination of a 5-HT3 receptor antagonist and Dexamethasone before each fraction and on the day after each fraction if Radiation Therapy is not planned for that day.
Moderate-emetic-risk radiation therapy
• (Reworded for clarity) Adult patients who are treated with moderate-emetic-risk Radiation Therapy should be offered a 5-HT3 receptor antagonist before each fraction, with or without Dexamethasone before the first five fractions. Low-emetic-risk radiation therapy
• (Updated) Adult patients who are treated with Radiation Therapy to the brain should be offered rescue Dexamethasone therapy. Patients who are treated with Radiation Therapy to the head and neck, thorax, or pelvis should be offered rescue therapy with a 5-HT3 receptor antagonist, Dexamethasone, or a Dopamine receptor antagonist.
Minimal-emetic-risk radiation therapy
• (Updated) Adult patients who are treated with minimal-emetic-risk radiation therapy should be offered rescue therapy with a 5-HT3 receptor antagonist, Dexamethasone, or a Dopamine receptor antagonist.
Concurrent radiation and antineoplastic agent therapy
• (Updated) Adult patients who are treated with concurrent radiation and antineoplastic agents should receive antiemetic therapy that is appropriate for the emetic risk level of antineoplastic agents, unless the risk level of the radiation therapy is higher. During periods when prophylactic antiemetic therapy for antineoplastic agents has ended and ongoing radiation therapy would normally be managed with its own prophylactic therapy, patients should receive prophylactic therapy that is appropriate for the emetic risk of the radiation therapy until the next period of antineoplastic therapy, rather than receiving rescue therapy for antineoplastic agents as needed.
Pediatric Patients
High-emetic-risk antineoplastic agents
• (Updated) Pediatric patients who are treated with high-emetic-risk antineoplastic agents should be offered a three-drug combination of a 5-HT3receptor antagonist, Dexamethasone, and Aprepitant.
• (New) Pediatric patients who are treated with high-emetic-risk antineoplastic agents who are unable to receive Aprepitant should be offered a two-drug combination of a 5-HT3 receptor antagonist and Dexamethasone.
• (New) Pediatric patients who are treated with high-emetic-risk antineoplastic agents who are unable to receive Dexamethasone should be offered a two-drug combination of Palonosetron and Aprepitant.
Moderate-emetic-risk antineoplastic agents
• (Reworded for clarity) Pediatric patients who are treated with moderate-emetic-risk antineoplastic agents should be offered a two-drug combination of a 5-HT3receptor antagonist and Dexamethasone.
• (New) Pediatric patients who are treated with moderate-emetic-risk antineoplastic agents who are unable to receive Dexamethasone should be offered a two-drug combination of a 5-HT3 receptor antagonist and Aprepitant.
Low-emetic-risk antineoplastic agents
• (New) Pediatric patients who are treated with low-emetic-risk antineoplastic agents should be offered Ondansetron or Granisetron.
Minimal emetic risk antineoplastic agents
• (New) Pediatric patients who are treated with minimal-emetic-risk antineoplastic agents should not be offered routine antiemetic prophylaxis.
Antiemetics: American Society of Clinical Oncology Clinical Practice Guideline Update. Hesketh PJ, Kris MG, Basch E, et al. DOI: 10.1200/JCO.2017.74.4789 Journal of Clinical Oncology – published online before print July 31, 2017
Antiemetics American Society of Clinical Oncology Clinical Practice Guideline Update
SUMMARY: The ASCO guideline for Antiemetics in oncology was updated by the ASCO Expert Panel following a systematic review of 41publications from November 2009 thru June 2016. The recommendations in this guideline are most definitive for adults who are treated with single-day IV chemotherapy. This topic has been divided into Part I and Part II for easy reading. Part II is continued in the second article of this e NewsLetter.
Guideline Question: What are the most effective strategies for preventing or managing nausea and vomiting due to antineoplastic agents or radiation therapy?
Target Population: Adults and children who receive antineoplastic agents and adults who undergo radiation therapy for cancer.
Target Audience: Medical and Radiation Oncologists, Oncology Nurses, Nurse Practitioners, Physician Assistants, Oncology Pharmacists, and Patients with cancer
KEY RECOMMENDATIONS – PART I
Adult Patients
High-emetic-risk antineoplastic agents
• (Updated) Adult patients who are treated with Cisplatin and other high-emetic-risk single agents should be offered a four-drug combination of a Neurokinin 1 (NK1) receptor antagonist, a Serotonin (5-HT3) receptor antagonist, Dexamethasone, and Olanzapine. Dexamethasone and Olanzapine should be continued on days 2 to 4.
• (Updated) Adult patients who are treated with an Anthracycline combined with Cyclophosphamide should be offered a four-drug combination of an NK1 receptor antagonist, a 5-HT3 receptor antagonist, Dexamethasone, and Olanzapine. Olanzapine should be continued on days 2 to 4.
Moderate-emetic-risk antineoplastic agents
• (Updated) Adult patients who are treated with Carboplatin AUC 4 or more should be offered a three-drug combination of an NK1 receptor antagonist, a 5-HT3 receptor antagonist, and Dexamethasone.
• (Updated) Adult patients who are treated with moderate-emetic-risk antineoplastic agents, excluding Carboplatin AUC 4 or more, should be offered a two-drug combination of a 5-HT3 receptor antagonist (day 1) and Dexamethasone (day 1).
• (Updated) Adult patients who are treated with Cyclophosphamide, Doxorubicin, Oxaliplatin, and other moderate-emetic-risk antineoplastic agents that are known to cause delayed nausea and vomiting may be offered Dexamethasone on days 2 to 3.
Low-emetic-risk antineoplastic agents
• (Updated) Adult patients who are treated with low-emetic-risk antineoplastic agents should be offered a single dose of a 5-HT3 receptor antagonist or a single 8-mg dose of Dexamethasone before antineoplastic treatment.
Minimal-emetic-risk antineoplastic agents
• (Reworded for clarity) Adult patients who are treated with minimal-emetic-risk antineoplastic agents should not be offered routine antiemetic prophylaxis.
Antineoplastic combinations
• (Reworded for clarity) Adult patients who are treated with antineoplastic combinations should be offered antiemetics that are appropriate for the component antineoplastic agent of greatest emetic risk.
Adjunctive drugs
• (Updated) Lorazepam is a useful adjunct to antiemetic drugs, but is not recommended as a single-agent antiemetic.
Cannabinoids
• (New) Evidence remains insufficient for a recommendation regarding treatment with medical marijuana for the prevention of nausea and vomiting in patients with cancer who receive chemotherapy or radiation therapy. Evidence is also insufficient for a recommendation regarding the use of medical marijuana in place of the tested and US FDA-approved cannabinoids, Dronabinol and Nabilone, for the treatment of nausea and vomiting caused by chemotherapy or radiation therapy.
Complementary and alternative therapies
• (Reworded for clarity) Evidence remains insufficient for a recommendation for or against the use of ginger, acupuncture/acupressure, and other complementary or alternative therapies for the prevention of nausea and vomiting in patients with cancer.
High-dose chemotherapy with stem cell or bone marrow transplantation
• (Updated) Adult patients who are treated with high-dose chemotherapy and stem cell or bone marrow transplantation should be offered a three-drug combination of an NK1 receptor antagonist, a 5-HT3 receptor antagonist, and Dexamethasone.
Multiday antineoplastic therapy
• (Reworded for clarity) Adult patients who are treated with multiday antineoplastic agents should be offered antiemetics before treatment that are appropriate for the emetic risk of the antineoplastic agent administered on each day of the antineoplastic treatment and for 2 days after the completion of the antineoplastic regimen.
• (Strengthened) Adult patients who are treated with 4- or 5-day Cisplatin regimens should be offered a three-drug combination of an NK1 receptor antagonist, a 5-HT3 receptor antagonist, and Dexamethasone.
Continued….. in Article 2 of this e NewsLetter
Antiemetics: American Society of Clinical Oncology Clinical Practice Guideline Update. Hesketh PJ, Kris MG, Basch E, et al. DOI: 10.1200/JCO.2017.74.4789 Journal of Clinical Oncology – published online before print July 31, 2017
FDA’s First Tissue/Site-Agnostic Approval
The FDA for the first time approved a cancer treatment based on specific genetic biomarker, rather than location in the body where the tumor originated. KEYTRUDA®, an anti-PD1 monoclonal antibody was granted accelerated approval for treatment of adult and pediatric patients with unresectable or metastatic, MicroSatellite Instability-High (MSI-H) or MisMatch Repair deficient (dMMR) solid tumors that have progressed following prior treatment and who have no satisfactory alternative treatment options or with MSI-H or dMMR ColoRectal Cancer that has progressed following treatment with a Fluoropyrimidine, Oxaliplatin, and Irinotecan. MMR gene deficiency can be detected by ImmunoHistoChemistry and MSI testing is performed using a PCR based assay.
KEYTRUDA® (Pembrolizumab)
The FDA on May 23, 2017 granted accelerated approval to KEYTRUDA® for adult and pediatric patients with unresectable or metastatic, MicroSatellite Instability-High (MSI-H) or MisMatch Repair deficient (dMMR) solid tumors that have progressed following prior treatment and who have no satisfactory alternative treatment options or with MSI-H or dMMR ColoRectal Cancer that has progressed following treatment with a Fluoropyrimidine, Oxaliplatin, and Irinotecan. KEYTRUDA® is a product of Merck and Co., Inc.
Late Breaking Abstract – ASCO 2017 Targeted Therapy Based on Genomic Profiling Improves Overall Survival
SUMMARY: Tumor genomic profiling enables the identification of specific genomic alterations and thereby can provide personalized treatment options with targeted therapies that are specific for those molecular targets. A genomic test can be performed on a tumor specimen or on cell-free DNA in plasma (“liquid biopsy”) or an ImmunoHistoChemistry (IHC) test can be performed on tumor tissue for protein expression that demonstrates a genomic variant known to be a drug target, or to predict sensitivity to a chemotherapeutic drug. Next-generation sequencing (NGS) platforms or second-generation sequencing unlike the first-generation sequencing, known as Sanger sequencing, perform massively parallel sequencing, which allows sequencing of millions of fragments of DNA from a single sample. With this high-throughput sequencing, the entire genome can be sequenced in less than 24 hours. Recently reported genomic profiling studies performed in patients with advanced cancer suggest that actionable mutations are found in 20-40% of patients’ tumors.
ProfiLER is an ongoing, molecular profiling clinical trial, developed to guide treatment by exploring genomic alterations in cancer cells of patients with advanced malignancy. DNA extracted from either archival or fresh tumor tissue was analyzed by next-generation sequencing of 60 cancer-related genes and whole-genome comparative genomic hybridization, a methodology for rapidly comparing DNA samples. A multidisciplinary board of experts in genomic profiling analyzed the genomic test results data and recommended molecular targeted therapies, when actionable mutations were found. These therapies were either commercially available drugs or those being tested in early clinical trials.
This study enrolled 2,676 patients to date and 1,944 tumors were analyzed. They included colorectal, gynecologic, breast, brain, and head and neck cancers, as well as sarcomas. Actionable mutations were found in 1,004 tumor samples (52%), 609 patients had only 1 actionable mutation, and 394 patients had 2-6 actionable mutations. The most common actionable mutation involved the PI3K/mTOR pathway. The molecular tumor board recommended molecularly targeted treatments to 676 patients (35% of 1,944 patients tested). Of these 676 patients, 143 received the recommended treatment, mostly through enrollment in a clinical trial. The rest of the 533 patients were unable to receive the recommended treatment because of poor health, rapid tumor progression, not meeting eligibility criteria for a clinical trial, or difficulty obtaining off-label commercially available drugs.
The Overall Survival rates for the 143 patients who received targeted therapies based on genomic testing was then compared with the 533 patients who did not. The Overall Survival rate at 3 years for those patients who received the recommended molecular targeted therapy was 53.7% compared with 46.1% for those patients who did not. The 5-year Overall Survival rate was also higher for patients who received molecular targeted therapy compared to those who did not (34.8% versus 28.1%).
This study validated that comprehensive genomic profiling can be performed in routine clinical practice, to select patients for targeted cancer therapies. The TAPUR (Targeted Agent and Profiling Utilization Registry) study conducted by ASCO is underway and is aimed at collecting “real-world” data on clinical outcomes, to help learn additional uses of molecularly-targeted cancer drugs, outside of indications approved by the FDA. Routine molecular screening of advanced refractory cancer patients: An analysis of the first 2490 patients of the ProfilER Study. Tredan O, Corset V, Wang Q, et al. J Clin Oncol 35, 2017 (suppl; abstr LBA100)
FDA Approves KEYTRUDA® for MicroSatellite Instability-High (MSI-H) or MisMatch Repair Deficient (dMMR) Solid Tumors
SUMMARY: The FDA on May 23, 2017, granted accelerated approval to KEYTRUDA® (Pembrolizumab) for adult and pediatric patients with unresectable or metastatic, MicroSatellite Instability-High (MSI-H) or MisMatch Repair Deficient (dMMR) solid tumors that have progressed following prior treatment and who have no satisfactory alternative treatment options or with MSI-H or dMMR ColoRectal cancer that has progressed following treatment with a Fluoropyrimidine, Oxaliplatin, and Irinotecan.
The DNA MisMatchRepair (MMR) system is responsible for molecular surveillance and works as an editing tool that identifies errors within the microsatellite regions of DNA and removes them. Defective MMR system leads to MSI (Micro Satellite Instability) and hypermutation, triggering an enhanced antitumor immune response. MSI (Micro Satellite Instability) is therefore a hallmark of defective/deficient DNA MisMatchRepair (MMR) system and occurs in 15% of all colorectal cancers. Defective MisMatchRepair can be a sporadic or heritable event. Approximately 65% of the MSI colon tumors are sporadic and when sporadic, the DNA MisMatchRepair gene is MLH1. Defective MisMatchRepair can also manifest as a germline mutation occurring in 1 of the 4 MisMatchRepair genes which include MLH1, MSH2, MSH6, PMS2. This produces Lynch Syndrome (Hereditary Nonpolyposis ColoRectal Carcinoma – HNPCC), an autosomal dominant disorder and is the most common form of hereditary colon cancer, accounting for 35% of the MSI colorectal cancers. MSI tumors tend to have better outcomes and this has been attributed to the abundance of tumor infiltrating lymphocytes in these tumors from increased immunogenicity. These tumors are susceptible to PD-1 blockade and respond to treatment with checkpoint inhibitors such as KEYTRUDA® (N Engl J Med 372:2509-2520, 2015). Other MSH-H and dMMR tumors include, Endometrial and GastroIntestinal tumors and to a lesser extent Breast, Prostate, Bladder and Thyroid tumors.
MSI (Micro Satellite Instability) testing is performed using a PCR based assay and MSI-High refers to instability at 2 or more of the 5 mononucleotide repeat markers and MSI-Low refers to instability at 1 of the 5 markers. Patients are considered Micro Satellite Stable (MSS) if no instability occurs. MSI-L and MSS are grouped together because MSI-L tumors are uncommon and behave similar to MSS tumors. Tumors considered MSI-H have deficiency of one or more of the DNA MisMatchRepair genes. MMR gene deficiency can be detected by ImmunoHistoChemistry (IHC). MLH1 gene is often lost in association with PMS2.
KEYTRUDA® is a fully humanized, Immunoglobulin G4, anti-PD-1, monoclonal antibody, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2, thereby undoing PD-1 pathway-mediated inhibition of the immune response and unleashing the tumor-specific effector T cells. This unique FDA approval was based on data from 149 patients with MSI-H or dMMR tumors (15 cancer types), enrolled across five uncontrolled, multi-cohort, multi-center, single-arm clinical trials. Ninety patients had colorectal cancer and 59 patients were diagnosed with one of 14 other cancer types. KEYTRUDA® was administered at 200 mg IV every 3 weeks or 10 mg/kg every 2 weeks until disease progression or unacceptable toxicity, for a maximum period of 24 months. The median age was 55 years and over a third of the patients were 65 yrs or older. The major efficacy outcome measures were Objective Response Rate (ORR) and Duration of Response. The identification of MSI-H or dMMR tumor status for the majority of patients (135/149) was prospectively determined using local laboratory-developed, Polymerase Chain Reaction (PCR) tests for MSI-H status or ImmunoHistoChemistry (IHC) tests for MMR deficiency.
The Objective Response Rate (ORR) with KEYTRUDA® was 39.6% with 7.4% Complete Responses and 32.2% Partial Responses. The ORR was 36% in patients diagnosed with ColoRectal Cancer and 46% in patients with any of the other cancer types. Responses lasted six months or more for 78% of those patients, who responded to KEYTRUDA®.
The most common toxicities included fatigue, rash, pruritus, nausea, diarrhea, decreased appetite, cough and dyspnea. Pembrolizumab is associated with immune-mediated side effects, including pneumonitis, colitis, hepatitis, endocrinopathies, and nephritis. The Prescribing Information for KEYTRUDA® includes a “Limitation of Use” stating that the safety and effectiveness of KEYTRUDA® in pediatric patients with MSI-H Central Nervous System cancers have not been established.
This is the first FDA approval of a cancer treatment, based on specific genetic biomarker, rather than location in the body where the tumor originated.
Pembrolizumab for patients with previously treated, mismatch repair-deficient microsatellite instability-high advanced colorectal carcinoma: phase 2 KEYNOTE-164 study. Dung L, Thierry A, Won KT, et al. Ann Oncol (2016) 27 (suppl_2): ii79.
First-line pembrolizumab versus investigator-choice chemotherapy for mismatch repair–deficient or microsatellite instability–high metastatic colorectal Carcinoma. Luis D, Dung L, Takayuki Y, et al. Annals of Oncology (2016) 27 (2): 1-85. 10.1093/annonc/mdw199
A Tool to Predict Chemotherapy Related Toxicity in Elderly Patients
SUMMARY: Cancer in general is a disease of the elderly with two thirds of all cancers and close to three fourths of cancer mortality occurring in individuals 65 years of age or older. Elderly patients are less likely to be offered chemotherapy, as these patients are at an increased risk for chemotherapy related toxicity, compared to their younger counterparts. This may be due to a variety of reasons including decreased bone marrow reserve with aging and an increased risk of chemotherapy-related myelosuppression, inability to endure treatment due to decreased physiologic reserves, as well as impaired clearance of chemotherapy drugs due to decreased renal function. Further, cognitive and hearing impairment along with a poor support system also play an important role in the elderly, not seeking medical care, in a timely manner. Unfortunately, elderly patients are often excluded from participating in clinical trials, which makes it even more difficult to weigh the risks and benefits of chemotherapy in this patient group. Patient Performance Status is often taken into consideration to predict tolerance to chemotherapy as well as outcomes, although it remains unclear if this is a valid predictor of toxicity in elderly patients. Identifying elderly patients who are at risk for developing chemotherapy related toxicity, remains an unmet need.
In this study, researchers developed a predictive model for chemotherapy toxicity, which consisted of 11 questions pertaining to age, tumor type, treatment, lab values and geriatric assessment, using data collected from a prospective longitudinal study of 500 patients, 65 years or older. Based on the answers to the 11 questions, a score for the risk of chemotherapy toxicity was calculated and three risk groups were created – Low (0-5 points), Medium (6-9 points) and High (10-19 points). In this Development cohort, the risk for chemotherapy toxicity correlated with an increasing risk score with 53% of patients experiencing grade 3 or higher chemotherapy toxicity.
The authors then validated the predictive model in an independent cohort of elderly adults (N=250) with a median age of 73 years. It was noted that more than one half of patients in the Validation cohort (58%) experienced grade 3 or more toxicity of whom 34% experienced hematologic toxicity and 55% experienced nonhematologic toxicity. The risk of toxicity increased with increasing risk score (36.7% for low risk cohort, 62.4% for medium risk cohort and 70.2% for high risk cohort; P<0.001). These findings were not statistically different from the Development cohort. Interestingly, there was no association between Karnofsky Performance Status and chemotherapy toxicity (P=0.25).
In elderly patients receiving chemotherapy, this tool is best used to distinguish low and high risk patients but is unable to distinguish moderate and high risk patients. Further, this model was only able to predict grade 3 or more toxicity but not grade 2 toxicity, and this may be equally relevant in elderly patients. Because patients included in this study had solid tumors and did not receive biologics or high-dose chemotherapy, these results apply primarily to patients with solid tumors who receive chemotherapy.
The authors concluded that this prediction model is easy to use in clinical practice and allows Oncology Health Care Providers to help elderly patients make informed decisions and also anticipate potential toxicities in high risk elderly patients and take preventive measures accordingly. Validation of a Prediction Tool for Chemotherapy Toxicity in Older Adults with Cancer. Hurria A, Mohile S, Gajra A, et al. J Clin Oncol 2016;34:2366-2371